US2207771A - Thermoelectric safety valve and switch - Google Patents

Description

July 16, 1940. T. T. ARDEN THERMOELECTRIC SAFETY VALVE AND SWITCH Filed April 29, 1936 5 Sheets-Sheet l July 16, 1940. ARDEN 2,207,771

THERMOELECTRIC SAFETY VALVE AND SWITCH Filed April 29, 1936 I 3 Sheets-Sheet 2 0 M. wa- .331;

"Hill! 65 ,1 ml

' lllll d July 16, 1940. T. 'r. ARDEN 2,207,771

THERMOELECTRIC SAFETY VALVE AND SWITCH Filed April 29, 1936 3 Sheets-Sheet 5 "mum/E ema ls, 16, 1940 UNITED STATES PATENT OFFICE Thomas T. Arden, Milwaukee, Wis assignor to Milwaukee Gas Specialty Company, m1-

waukee, Wia, a corporation of Wisconsin 7 Application April 29,

I 19 Claims.

This invention relates to a thermoelectric safety valve and switch and may be characterized as an improvement upon the devices shown and described in the copending applications of John H. Thombery and Harold A. Mantz, Serial No.

743,382, filed September 10, 1934, and Serial No.

14,551, flied April 4, 1935.

In the flrst of the above mentioned copending applications a thermocouple responsive to the 10 heat of the pilot flame energizes an electromagnet to hold a gas valve in open position as long as the pilot flame is burning. If the pilot flame is extinguished, the electromagnet is deenergized and the gas valve moves to closed position.

In the second application above mentioned, a thermocouple responsive to the heat of the pilot flame energizes an electromagnet to hold an electric switch closed so long as the pilot flame is burning. The switch controls a circuit for a go remotely disposed electrically operated valve. If

the pilot flame is extinguished the electromagnet is deenergized and the switch opens the circuit for the remotely disposed electrically operated valve and, as this circuit is opened, the remotely 85 disposed valve moves to closed position.

The object of the present invention is to provide a thermoelectric safety valve and switch in which a thermocouple responsive to the heat of the pilot flame energizes an electromagnet, which so electromagnet performs the dual function of holding the gas valve in open position and simultaneously the electric switch closed. If the pilot flame is extinguished, the electromagnet, which is energized by the thermocouple, is deenergized 35 and the switch is opened and the gas valve moved to closed position.

By the dual function thus performed the device is adapted for controlling a valve which may be disposed in the gas supply line to the pilot 40 device and simultaneously an electric circuit for a remotely controlled valve which may be disposed in the main gas supply line to the burner.

It is to be understood, however, that the switch of the present device may, within the scope of 5 my present invention, control electric circuits for other or equivalent devices and that the valve of the present device may be arranged elsewhere than in the gas supply line to the pilot device.

Another object is to provide a combined 50 thermoelectric valve and switch in which the switch and electromagnet will not be exposed to the gas, the flow of which is controlled by the I valve, and in which at the same time the switch will be in close proximity to the valve, where it 5. may be held closed by the elect omagnet, whih 1936, Serial No. 76,988

is energized by the thermocouple and which serves to hold the valve open.

Another object is to so combine the valve and switch means of the thermoelectric device that a single resetting device may be employed for re- 5 setting the valve to open position and the switch to closed position, and to provide a single resetting device for this purpose.

According to one embodiment of the invention, the device is a two chamber device with the 10 valve operable in one chamber and the switch and electromagnet disposed in the other chamber.

Another embodiment of the invention is a three chamber device with the switch disposed in one chamber, the valve operable in the second chaml5 ber, and the electromagnet disposed in the third chamber.

Further objects and'advantages of the invention will be apparent from the following detailed description, taken in conjunction with the accompanying drawings, in which:

Figure 1 is a fragmentary and more or less diagrammatic view showing an embodiment of the present invention in a pilot burner and main burner gas supply system;

Figure 2 is a top plan view of the thermoelectric safety valve and switch with the connected thermocouple partially in section;

Figure 3 is a vertical section on an enlarged scale, taken on the line 3-3 of Figure 2;

Figure 4 is an elevational view partially in section, looking from the right-hand side of Figure 2;

Figure 5 is a top plan view of a modified form 'of thermoelectric safety valve and switch embodying the present invention;

Figure 6 is a vertical section taken on the line 86 of Figure 5; and

Figure "l is an elevational view, partially in section, looking from the right hand side in Figure 5. 40

Referring to the drawings, the pipe Ill, which may be the gas supply pipe for the main burner (not shown) is provided with an electrically operated valve I! of a type well known in the art.

The heater, appliance, or the like, is diagrammatically indicated at H, and the main burner, which may be associated therewith in any suitable or preferred manner, may be controlled by the valve I2. This valve has electrically controlled mechanism connected into an electric circuit i5 5 which may be provided with a thermostat IE to be opened or closed in accordance with the temperature of the room heated by the heater, where the heater is a room heater, or the thermostat It may be arranged to be opened and closed 5 in accordance .with the temperature of the water in the tank, where the heater is a water heater, or otherwise as desired. The circuit i5 may include the secondary winding of a transformer I1, which may be connected to a suitable source oi current.

Associated with the main burner in the usual or in any suitable or preferred manner, isa pilot burner |8 which is intended to remain lighted and which may be of any suitable construction. This pilot burner I6 is supplied with fluid fuel by a tube l8 connected to the pipe l6 ahead of the valve l2.

The thermoelectric safety valve and switch shown in Figures 1 to 4 inclusive, is indicated in its entirety at 28, and is shown interposed in the fuel supply tube l8 for the pilot burner l8. It comprises a lower valve casing 2| and a hood 22. These two parts are held together by screws 23. a The valve casing is hollow and has a partition wall 24 dividing the interior thereof into an inlet chamber 25 and an outlet chamber. 26. The tapped inlet opening at the inlet chamber is adapted to receive the gas inlet pipe and the tapped outlet opening at the outlet chamber is adapted to receive the gas outlet pipe which. extends, for example, to the pilot burner l8. Formed in the partition wall 24 is an opening 28 surrounded by a valve seat against which a valve member 28 is resiliently pressed by a compression spring 38 when the electromagnet, indicated in its entirety at 3|, is deenergized as will hereinafter appear.

The electromagnet 3| is disposed within the hood 22 and comprises a U-shaped magnet frame 32 provided about each of its legs with a coil 33. The magnet frame 32 is held rigidly to a magnet mounting plate 34 by means of a bracket 35 which is secured to the plate 34 by screws 36. The plate 34 is, in turn, rigidly secured te the hood 22 by a screw 31. A name plate 38 is secured etxernally to the top of the hood by a screw 38.

The magnet armature 42 is adapted to have engagement with the end portions of the U- shaped magnet 32. This armature is guided for reciprocatory movement within upright guide lugs 43 onan armature guide 44 which is secured to the hood 22 by screws 45. The armature 42 has attached thereto, by upwardly extending bent-over portions 46, acradle 41 which, in turn, is connected to the upper end of the fiber valve stem 48 by means of a U-washer 48 engaging in a groove in theupper end of the stem 48 and cooperating with the inturned lower end of the cradle 41. A limited universal connection is thus provided between the armature 42 and theupper end of the stem 48. a

The stem 48 has a brass contact ring 58 against which contact fingers 5| yieldingly press. These contact fingers 5| are riveted at 52 to a switch base 53 which extends out and is secured by the screws 23 between the valve casing 2| and the hood 22. Insulating discs 55 and 56 are interposed between the switch base 53 and the hood 22 and secured between the valve casing 2| and the hood, the upper disc 55 extending in'over the adjacent portions of the contact fingers 5|. A valve body gasket 51 is interposed between the lower disc 56 and the valve casing 2|- The contact fingers 5| have terminal extensions 58 (Fig. 2) which extend out and are connected to terminal washers 58 and terminal screws 68. The terminal screws 68 are connec ed by conductors 6| and .62 through the circuit l5 to suitable terminals 63 for the electrically controlled actuating mechanism within the housing carried by the electrically operated valve l2.

The valve disc member 28 is secured to the stem 48 by a diametrical pin 65. The spring 38 is coiled about the stem 48 and confined between the valve disc 28 and a valve stem washer 66 which has packing 66 above itso that gas cannot escape from the valve casing 2| into the hood 22. The under surface of the valve disc 28 has a gasket 68 clamped in a recess in the disc and between the disc and a washer 18, by the resetting stem 1|, the upper reduced end of which is threaded into the valve disc 28, as shown.

The resetting stem 1| extends downwardly through the opening 28 and out through the bottom of the valve casing 2| into a tubular boss on the bottom of the casing. Suitable packingis provided at 14 to seal the valve casing against gas leakagealong the stem 1|. Fixed upon the lower end of the stem 1| by a pin 15 is a resetting button 16. This button is slidable in the recess in the boss on the bottom of the valve casing and a compression spring 18 is coiled about the stem 1| and confined between the button 16 and the stem packing washer 18. The

upper end of the button 16 may be recessed to receive the lower end of the spring 18 as shown. In order to prevent unwarranted actuation of the button 16 a closure member or cap 82 is threaded upon the boss at the bottom of the casing 2| and over the button 16 completely to enclose the button. Ln order to reset the valve disc and switch it is necessary to remove this cap 82.

v A suitable thermocouple, comprising'an outer tubular element 88 which, at one end, is welded to the inner element 8| as shown at 82, for the purpose of providing a hot junction between the two members, is disposed with the junction in preximity te the pilot flame, as shcwn more or less diagrammatically in Figure 1, so as to be responsive to the heat of the pilot flame. The external element 88 is joined at its opposite end, as by welding or the like, at 83, to a tubular couple connector 84. The opposite end of the tubular connector, which may be formed of copper, or other suitable metal, is joined as by welding or the like at 85, to the adjacent end of the lead tube 86. Extending through the tube 86 is the lead wire 81 which may be an insulated wire and which, within the connector 84, is joined at 88 to the internal element 8| of the thermocouple. The thermocouple elements 88 and 8| are formed of dissimilar metals such as Constantan and Chromel, Chromel and Copel, or any other dissimilar metals which, when heated at the junction therebetween, are adapted to produce a thermoelectric current.

The lead tube 86, which may be formed of copper, extends to the thermoelectric valve and switch device 28 and is secured, as by means of a welded joint at 98', within a reduced portion 88 of a connector I88 which is threaded into and electrically contacts the hood 22. Within the connector I88 is provided an insulating sleeve |8| disposed about the adjacent end of the conductor 81 and enclosing the connector I82 between the conductor 81 and the terminal conductor I83 of one of the coils 33. The other coil terminal is connected to the connector I88 as shown at I85. Thus a circuit is completed through the coils 33 about the legs of the magnet 32 and the conductors 86 and 81 leading to the hot thermocouple junction.

The operation of the device shown in Figures 1 to 4, inclusive, is as follows: 4

When the pilot flanie I8 is burning the heat of the pilot fiame'upon the junction 92 of the thermocouple produces a thermoelectric current in the coils 33 of the electromagnet 3i. The magnet frame 32 and armature 42 are preferably formed of Permaloy, Hypernik," or a similar alloy of relatively low magnetic reluctance and, as a result, the relatively weak thermoelectric current produces a magnetic field in the magnet frame and armature of sufflcient strength so that when the magnet armature is placed in contact with the ends of the magnet frame by pushing the reset button I6, the magnetic attraction between the magnet frame and the armature holds the armature in raised position against the frame with a force greater than the force exerted by the springs 30 and I8, thereby holding the contact ring 50 in contact with the contacts and the valve member 29 in open position so long as the pilot flame is burning.

If the pilot light goes out, the thermoelectric current through the electromagnet 3I ceases and the springs 30 and I8 move the valve member 29 to closed position, and, simultaneously, the contact ring 50 downwardly into open position out of engagement with the contacts 5I. The operation of the springs in closing the valve and opening the switch is aided by gravity if the device is installed vertically, as shown, but the springs are preferably of suflicient tension to close the valve and open the switch without the aid of gravity, whereby the device may-be installed in any desired position. The springs also assure detachment of the armature from the electromagnet upon deenergization of same and notwithstanding any residual magnetization therein. The closing of the valve 29 shuts oil! the supply of gas to the pilot burner and the opening of the switch opens the circuit I5 for the safety control valve I2, whereupon this valve moves to closed position to close oil the supply of gas to the main burner.

The current produced by the thermocouple at the pilot tip I8 is not sufllcient to energize the magnet sufii'ciently to draw the armature upwardly from its lowermost position and therefore the combined valve and switch is reset by removing the cap 82 and pushing the reset button I6 sumciently to raise the armature 42 into contact with the magnet frame. -The pilot can then be relighted, but the stem II must be held in the position to retain the armature against the electromagnet for a suflicient period to assure that the thermoelectric current has energized the electromagnet. The device is thereby reconditioned, and upon release of the resetting button the energization of the electromagnet by means of the thermocouple, when the thermocouple is responsive to the heat of the pilot flame, will hold the valve 29 open and the switch closed as long as the pilot flame is burning.

After the connections are made between the electromagnet and the tube 96 and conductor 91,

and between the electromagnet and the connector I00, the space between the electromagnet and the upper portion of the hood is filled with sealing compound, indicated at IIO, for holding the parts in position and sealing the same in place. This compound also seals the hood against the leakage of any gas which may leak up into the hood past the valve stem 48.

The modified form of thermoelectric safety 75;switch and valve shown in Figures 5 to '7, in-

tapped outlet opening at the outlet chamber is adapted to receive the gas outlet pipe which extends, for example, to the pilot burner. 'Formed in the partition wall is a valve opening I 34 surrounded by a valve seat against which a valve member I35 is resiliently pressed by compression spring I36 when the electromagnet, indicated at I31, is deenergized.

The electromagnet I31 is disposed within the hood I 32, and, as in the preceding embodiment, comprises a U-shaped magnet frame I38 pro-- vided about each of its legs with a coil I39. The

magnet frame is held rigidly to a magnet mounting plate I40 by means of a bracket which is secured to the plate by screws, as shown. The plate I40 is, in turn, rigidly secured to the hood I32 by a screw I4I. A name plate may be provided, as before.

The magnet armature I is adapted to have engagement with the end portions of the U-shaped magnet I38. This armature is guided, as before, for reciprocatory movement within upright guide lugs I46 on an armature guide I41 whichissecuredtothehood I32byscrews I48. The armature I45 has attached thereto by upwardly extending bent-over portions a cradle which, in turn, is connected to the upper end of the valve stem I50, preferably in a manner to provide limited universal connection as described in connection with the preceding embodiment of the invention.

The valve disc member I35 is secured to the lower end of the stem I50 by a cradle I52 which has an inturned upper end which cooperates with a ,U-shaped retainer I53 engaging in a oove in the lower end of the stem I50. A limited universal connection is thus provided between the valve member I35 and the lower end of the stem I50. The spring I36 is coiled about the stem I50 and confined between the flanged margin of the cradle I52 and a valve stem washer I55 which has packing I56 disposed above it and in a recess in the armature guide so that gas cannot escape from the valve casing I30 into the hood I32. The under surface of the valve disc I35 has a gasket I58 clamped in a recess-in the valve disc and between the disc and a washer by the resetting stem I60, the upper reduced end of which is threaded into the valve disc I35 as shown. i l i' The resetting stem I60 extends downwardly through the valve opening I34 down through an opening in the bottom of the valve casing I30, through switch casing I3I, and out through an opening in the bottom of the switch casing. Suitable packing is provided at I62 to seal the valve casing against gas leakage along the stem and into the switch casing. Fixed upon the lower end of the stem I60 is a resetting button I 63 secured upon the stem by a retainer spring I84 and a screw I65. In order to prevent unwarranted actuation of the button I63, a closure cap I 66 is threaded into the opening in the bottom of the switch casing and over the button I63 completely to enclose the button. This cap I66 is 7 removed to reset the valve as in the preceding embodiment of the invention .and the switch is reset by resetting the valve and replacing the cap I88 to engage its upper end with the disc I18 and press the contact disc I13 yieldingly against the contacts I14through the spring I88.

The stem I80 is siidable in an eyelet I88 which carries an insulating sleeve I88 and holds a washer I10 to the lower end of this sleeve. A ring I12 engages in a groove in the stem I80, and with the switch closed and the valve open this ring is positioned above the upper end of the sleeve I88 a distance less than the spacing of v the valve I38 above its seat. A contact disc I13 for bridging and connecting the contact fingers I14 has a central opening provided with an eyelet with which a shoulder I15 on the sleeve I88 is adapted to cooperate in the downward movement of the sleeve I88, which sleeve is slidable in an insulating disc I18 whichseats upon the upper end of the tubular extension of the cap I88.

The contact fingers I14 have down-turned ends (Figure 7) connected electrically to terminal bushings I18 and secured mechanically by said terminal bushings to an insulating terminal base I18 secured over a lateral opening in the switch casing I3I. Spacers are provided at I80, and the tubular extensions of the bushings I18 are headed at I M with a washer I82 interposed between the base I18 and each of these heads I8I-. Terminal screws I83 are threaded into each of the bushings I18, and these screws are provided with terminal washers I84. A terminal cover I85 is suitably secured by means of screws or the like (not'shown) over the terminal screws I83and the outer ends of the terminal bushings. The bottom of the cover I85 has openings provided with insulating grommets I88 through which the conductors corresponding, for example, with the conductors 8| and 82 of Figure 1 are led into the terminal cover I85 and connected to the respective terminal screws;

A coiled spring I88 surrounds the insulating sleeve I88 and is interposed between the contact disc I13 and, specifically, between the eyelet I15 thereof and the insulating disc I18. This spring I88 holds the contact disc I13 yieldingly against the contact arms I14 when the device is in the position shown in Figure 6, and at the same time permits the armature I45 to be pressed and held firmly against the ends of the legs of the magnet frame I38 without depending solely upon the yieldability of the contact arms I14. I lating bushing I80, enlarged to surround the retainer ring I12, is provided upon the stem I80,

5, 6 and 7 is as follows:

When the pilot flame, corresponding to the flame I8 of the preceding embodiment, is burning, the heat of the pilot fiame upon the junction of the thermocouple produces a thermoelectric current in the coils I38. The thermoelectric current produces a magnetic field in the magnet frame and armature of suflicient strength so that,

An insu-' when the magnet armature is placed in contact with the ends of the magnet frame by pushing 1 the reset button I83, the magnetic attraction holds the armature in raised position against the frame with a force greater than the force exerted by the spring means, thereby holding the contact disc I13 in contact with the contact arms I14 and the valve I38 in open position so long as the pilot flame is burning.

If thepilot light goes out, the thermoelectric current through the electromagnet I31 ceases, and the springs I38 and I82 move the valve member I38 to closed position and simultaneously the contact disc- I13 downwardly into open position out of engagement with the contact arms I 14. The closing of the valve shuts off the supply of gas to the pilot burner, and the opening of the switch opens the circuit for the safety control valve, whereupon this valve moves to closed position to close oi! the supply of gas to the main burner.

'In the downward movement of the stem I80, the retainerring I12 engages the upper end of the eyelet I 88 or insulating sleeve I88 and moves the same downwardly. Upon this downward movement of the. sleeve the shoulder I15 thereof engages the eyelet I15 or the contact disc I13 and moves the same downwardly into open posie tion out of engagement with the contact arms I14 against the tension of the spring I88.

In resetting the device, the retainer ring I12 moves upwardly with the stem I80. The contact I13 is not engaged with the contacts I14, however, untll the cap I88 is applied to position enclosing the resetting button. When thus applied, the upper end of the cap engages the disc I 18 'andpresses the contact I13 into engagement with the contacts I14 yieldingly through the spring I88. A gasket I 88 is preferably provided between the terminal base I18 and the switch casing BI, and gaskets. I 88' and I81 are preferably provided between the valve casing I80 and the hood I32, and between the valve casing I and the switch casing I3I, respectively.

It will be apparent from the foregoing description that the device of the present applicationis of relatively simple construction, iscomposed of relatively few parts which can be easily manufactured and assembled and which are advantageously related to each other; also a device which is easy of installation, and, working on the principle of a thermoelectric couple, is reliable and has advantages in operation. The present device also provides for controlling a gas valve and for simultaneously controlling an electric circuit.

It is to be understood that the invention is not to be limited to the embodiment illustrated and described, but is capable of a wide varietyoi embodiments within the scope of the appended claims, and'that changes may be made in'the details of construction, arrangement and relation of the parts. Furthermore, while the invention has been illustrated and described as employed in conjunction with a pilot light, it will be apparent that the invention may also be used as a safety device in connection with other devices,

' as, for example, the thermoelectric couple could be subjected to the heat of a main burner where it is desired that the gas valve be closed whenever the main burner goes out. Furthermore, the valve casing of the. present device may be connected into other. gas lines than the pilot supply line as shown, and the switch may control other circuits than a circuitfor a remotely disposed electrically operated valve in the gas line for the main burner.

I claim:

1. In combination, a valve casing having an inlet and an outlet, a hood on said casing, an electromagnet in said hood, a thermocouple responsive to the heat of a flame and connected to said electromagnet to energize same as long as said flame is burning, a switch base clamped between said valve casing and said hood, spaced contacts carried by said switch base, an armature disposed in the hood and adapted to be held to said electromagnet as long as the flame is burning, a valve stem carried by said armature and extending into the valve casing, a contact on said stem for bridging said first contacts when said armature is held to said electromagnet, a valve carried by said stem and disposed in said valve casing for controlling communication between the inlet and outlet of said casing, a washer on said stem, a spring between said washer and said valve member for closing said valve member and simultaneously moving the contact on the stem out of bridging engagement with said first contacts upon extinction of the flame, and packing between said washer and said switch base and about said stem for sealing the valve casing against valve leakage into the hood along said stem.

2. In combination, a valve casing having an inlet and an outlet, a hood on said casing, an electromagnet in said hood, a thermocouple responsive to the heat of a flame and connected to said electromagnet to energize same as long as said flame is burning, a switch base clamped between said valve casing and said hood, spaced contacts carried by said switch base, an armature disposed in the hood and adapted to be held to said electromagnet as long as the flame is burning, a valve stem carried by said armature and extending into the valve casing, a contact on said stem for bridging said first contacts when said armature is held to said electromagnet, a valve carried by said stem and disposed in said valve casingfor controlling communication between the inlet and outlet of said casing, a washer on said stem, a spring betweensaid washer and said valve member for closing said valve member and simultaneously moving the contact on the stem out of bridging engagement with said first contacts upon extinction of the flame, packing between said washer and said switch base and about said stem for sealing the valve casing against valve leakage into the hood along said stem, a resetting stem secured to the valve stem and extending down to the bottom of the casing, and a resetting button on said last stem. I

3. In combination, a valve casing, a hood on said casing, an electromagnet in the hood, an armature for said electromagnet, a valve stem carried by said armature, a valve member carried by said stem and operable in the valve casing, a switch base, switch contacts mounted upon said base and disposed in said hood, a contact carried by said stem and adapted for bridging said first contacts, and means for sealing said valve casing against leakage of gas into said hood.

4. In'combination, a valve casing, a hood on said casing, an electromagnet in the hood, an armature for said electromagnet, a valve stem carried by said armature, a valve. member carried by said stem and operable in the valve casing, a switch base, switch contacts mounted upon said base and disposed in said hood, a contact carried by said stem and adapted for bridging said first contacts, means for sealing said valve casing against leakage of gas into said hood, a reset ting stem secured to the lower end of the valve stem, a resetting button on said resetting stem, and a closure member removably secured to the valve casing and enclosing said resetting button.

5. In combination, a valve casing, a hood on said casing, a switch base clamped between said casing and said hood, an armature operable within the hood, a valve stem carried by said armature and extending through the switch base into the valve casing, a valve member on said valve stem and operable in the valve casing, spaced switch contacts disposed within said hood and mounted on said switch base, and a bridging contact member carried by said valve stem and adapted for bridging sad first contacts when the valve member is in open position.

6. In combination, a valve'casing, a hood on said casing, a switch base clamped between said casing and said hood, an armature operable within the hood, a valve stem carried by said armature and extending through the switch base into the valve casing, a valve member on said valve stem and operable in the valve casing, spaced switch contacts disposed within said hood and mounted on said switch base, a bridging contact member carried by said valve stem and adapted for bridging said first contacts when the valve member is in open position, and packing held to the switch base and about the valve stem for sealing the valve casing against gas leakage into the hood along said stem.

7. In combination, a valve casing, a switch casing sealed from said valve casing, an electromagnet casing also sealed from said valve casing, a valve operable in said valve casing, a switch operable in said switch casing, an electromagnet in said electromagnet casing, and a thermocouple connected to said electromagnet and adapted for simultaneously controlling said valve and said switch.

8. In combination, a valve casing having an inlet and an outlet, a hood on the top of said valve casing, an electromagnet in said hood, a thermocouple responsive to the heat of a flame and connected'to said electromagnet to energize same as long as said flame is burning, a switch casing on the bottom of said valve casing, an insulating contact base secured to the side of said switch casing, contact arms secured to said base and extending into the switch casing, an armature disposed in the hood and adapted to be held to said electromagnet as long as the flame is burning, a valve stem carried by said armature and extending into the valve casing, a valve carried by said stem. and operable in the valve casing, a stem coaxial with said first stem and extending into the switch casing, a contact member, means for yieldingly pressing said contact member into engagement with said contact arms, and means on said last stem for disengaging said contact member from said contact arms upon extinction of the flame.

9. In combination, a valve casing having an inlet and an outlet, a hood on the top of said valve casing, an electromagnet in said hood, a thermocouple responsive to the heat of a flame and connected to said electromagnet to energize same as long as said flame is burning, a switch casing on the bottom of said valve casing, an insulating contact base secured to the side of said switch casing, contact arms secured to said base and extending into the switch casing, an armature disposed in the hood and adapted to be held to said electromagnet as long as the flame is burning, a valve stem carried by said armature and extending into the valve casing, a valve carried by said stem and operable in the valve casing, a stem coaxial with said first stem and extending into the switch casing, a contact member, means for yieldingly' pressing said contact member into engagement with said contact arms, means on said last stem for disengaging said contact member from said contact arms upon extinction of the flame, and a resetting button on the lower end of said last stem for resetting the armature in contact with the electromagnet, the valve in open position and said last means in position to permit said contact member to be yieldingly pressed into engagement with said contact arms.

10. In combination, an electromagnet comprising a magnet member having coil means therefor, a thermocouple responsive to the heat of a flame and connected to the coil means of said electromagnet to energize same when said flame is burning, an armature adapted to be held to said electromagnet when same is energized by said 7 flame and movable to retracted position upon extinguishment of said flame, a valve adapted to be held in open position by said armature 11. In combination, housing means having means dividing the interior thereof into a valve casing part and another part, said valve casing part having a fuel inlet and a fuel outlet, electric switch contact means in said other part and sealed against the fuel passing through said valve casing part, an electromagnet comprising a magnet frame and coil means therefor, a thermocouple responsive to the heat of a flame and connected to the coil means of said electromagnet to energize same when said flame is burning, an armature adapted to be held to said electromagnet when same is energized by said flame and movable to retracted position upon extinguishment of said flame, a plunger carried by said armature and adapted to be actuated to return said armature to the position in which it is held by said electromagnet, means within said valve casing part and actuated by said plunger for controlling the flow of fuel through said valve casing part, and switch contact means within the other housing part and actuated into and out of cooperation with said first switch contactmeans by said plunger.

12. In combination, an electromagnet, a the!- mocouple adapted to be subjected to the heat of a flame and connected in circuit with said electromagnet, an armature adapted to be held attracted to said electromagnet when said electromagnet is energized by the heat of the flame on the thermocouple and operable to retracted position upon extinguishment ofthe flame, a 'valve adapted to be held in open position by said armature when the armature is in attracted position and operable to closed position upon movement of the armature to retracted position, and a switch adapted to be held closed by said armature when the armatur is in attracted position and operable to open position upon movement of the armature to retracted position.

13. In combination, on electromagnet, a thermocouple adapted to be subjected to the heat of a flame and connected in circuit with said electromagnet, an armature adapted to be held attracted to said electromagnet when said electromagnet is energized by the heat of the flame, a valve adapted to be held in open position by said armature when the armature is in attracted position, a switch adapted to be held closed by said armature when the armature is in attracted position, and spring means operable upon extinguishment of the flame for moving said armature to retracted position, said valve to closed position and said switch to open position.

14. In combination, an electromagnet, a thermocouple adapted to be subjected to the heat of a flame and connectedin circuit with said electromagnet, an armature adapted to be held attracted to said electromagnet when said electromagnet is energized by the heat of the flame, a valve adapted to be held in open position by said armature when the armature is in attracted position, a switch adapted to be held closed by said armature when the armature is in attracted position, means operable upon extinguishment of the flame for moving said armature to retracted position, said valve to closed position and said switch to open position, and means for resetting said armature to attracted position and operable simultaneously to open said valve and to'close said switch.

15. In combination, an electromagnet,a thermocouple adapted to be subjected to the heatoi' a flame and connected in circuit with said electromagnet to energize the same by the heat of the flame on the thermocouple, an armature adapted to be held attracted to said electromagnet when said electromagnet is energized by the heat of the flame on the thermocouple and operable to retracted position upon extinguishment of the flame, a controlling member having an operating position and a safety position, means for resetting said armature to attracted position and said controlling member to operating position, removable closure means for said last means, and -means requiring said armature to be in attracted position and said closure to be in place to hold said controlling member in operating position.

16. In combination, an electromagnet, a thermocouple adapted to be subjected to the heat of a flame and connected in circuit with said electromagnet to energize the same by the heat of the flame on the thermocouple, an armature adapted to be held attracted to said electromagnet when said electromagnet is energized by the heat of the flame on the thermocouple and operable to retracted position upon extinguishment of the flame, a controlling member having an operating position and a safety'position, means for resetting said armature to attracted position and said controlling memberto operating position, removable closure means for said last means, and means requiring said armature to be in attracted position and said closure means tobe in place to hold said controlling member in operating position, said controlling member being actuated to safety position by movement of said armature to retracted position when said closure means is in place and being disposed in safety position when said closure means is removed and said armature is in attracted position.

17. In combination, an electromagnet, a thermocouple adapted to be subjected to the heat of a flame and connected in circuit with said electromagnet to energize the same by the heat of the flame on the thermocouple, an armature adapted to be held attracted to said electromagnet when said electromagnet is energized by the heat of the flame "on the thermocouple and operable to retracted position upon extinguishment of the flame, a controlling member having an operating position and a safety position, means for resetting said armature to attracted position and said controlling member to operating position, removable closure means for said'last means, and a spring operative between said controlling member and said closure means for actuating said controlling member to operating position when the armature is in attracted position and the closure means is in place.

18. In combination, an electromagnet, athermocouple adapted to be subjected to the heat of a flame and connected in circuit with said electromagnet to energize the same by the heat of the flame on the thermocouple, an armature adapted to be held attracted to said electromagnet when said electromagnet is energized by the heat of the flame on the thermocouple and operable to retracted position upon extinguishment of the flame, a controlling member having an operating position and a safety position, means for resetting said armature to attracted position and said controlling member to operating position, removable closure means for said last means, and a spring operative between said controlling member and said closure means for actuating said controlling member to operating position when the armature is in attracted position and the closure means is in place, said controlling member being actuated to safety position against the tension of said spring upon movement of the armature to retracted position with the closure means in place and being disposed in safety position when said closure means is removed with the armature in attracted position.

19. In combination, an electromagnet, a thermocouple adapted to be subjected to the heat of a flame and connected in circuit with said electromagnet to energize the same by the heat of the flame on the thermocouple, an armature adapted to be held attracted to said electromagnet when said electromagnet is energized by the heat of the flame on the thermocouple and operable to retracted position upon extinguishment of the flame, a controlling member having an operating position and a safety position, means-for resetting said armature to attracted position and said controlling member to operating position, removable closure means for said last means, a spring operative between said controlling member and said closure means for actuating said controlling member to operating position when the armature is in attracted position and the closure means is in place, a stem connected to said armature, a sleeve on said stem and having abutment 1 means for cooperation with said controlling member, and an abutment on said stem and cooperable with said sleeve to actuate said controlling member to safety position against the tension of said spring upon movement of the armature to retracted position with said closure means in place.

THOMAS T. ARDEN.

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